Fix visible tiles revealing invisible tiles below

[Rewryte]

Summary

Bugfixes "Fix visible tiles revealing invisible tiles below"

Purpose of change

The way 3D vision currently handles tile visibility is by calculating visibility variables for the current z-level and have every z-level underneath inherit the same values. In cases where a tile on the current z-level should be visible but the tile underneath should not, the player will be able to see both tiles due to the non-visible tile underneath inheriting the visibility variables of the visible tile above it. Correcting this will fix #66040. Also a prerequisite for the lightmap changes in #67434.

Describe the solution

There are two parts to this solution:

1. Instead on updating the visibility cache on the current z-level only, we update the z-levels below as well, limited by the 3D vertical range setting.
2. In the tileset code, pull new variables from the visibility cache on each z-level to determine light level.

Naturally, these make processing visibility somewhat more CPU intensive. To compensate, map cache and visibility cache are no longer calculated every draw. Any event that alters these can simply call map::build_map_cache and map::update_visibility_cache instead. This involves the removal of the temporary fix introduced in #15868. The issues targeted by the fix (#15842 and #15854) are not reproducible.

Overall, these changes have a positive effect on draw performance leading to an 11% decrease in draw times.

Describe alternatives you've considered

Testing

Compiles ok.
Confirmed that invisible tiles no longer show as visible when viewing visible tiles on a higher z-level.

Before:

After:

Additional context

[Rewryte]

This will be in draft until optimizations are complete. Currently seeing a 57.6% increase in draw times.
Optimizations done. Now decreases draw times by ~11% using a 3D vertical range setting of 4.

[Rewryte]

Main post updated with optimization details. Currently fixing visual bugs resulting from the removal of map cache and visibility cache calculations from game::draw

[Maleclypse]

Is this intended to still be in draft? No stress if yes. It just reads as if it's ready to go possibly.

[Rewryte]

Is this intended to still be in draft? No stress if yes. It just reads as if it's ready to go possibly.

It's more or less done. Tests are passing on my end (MSYS2). Just pushed out one more fix to prevent cache bloat during tests. I'll likely bring it out of draft soon.

[ehughsbaird]

FYI, this resulted in a massive increase in test run times #68154.